Radio Frequency (RF) circuits such as filters, resonators and RF matching networks usually require one or more inductances and one or more capacitances. Tunable RF circuits may furthermore be desired to address multi-band and/or multi-standard operation. For such scenarios it is desirable to have tunable inductances and/or capacitances. Until today, tunable capacitors with high Quality factors (Q factors) are available in some technologies and approaches as, for example, varactor diodes, MEMS, switched capacitors, Barium Strontium Titanate (BST) capacitors, etc. However for tunable inductances the approaches usually suffer from issues, such as nonlinear behavior, not suited for high RF voltage and power levels or too low Q factors.